Magnesium-Rich Coatings

Transcription

1 Magnesium-Rich Coatings Dr. Kevin Kovaleski NAVAIR Materials Engineering Division Patuxent River, MD ASETS Denver, CO 1-3 September, 2009 NAVAIR Public Release Distribution: Statement A - "Approved for public release; distribution is unlimited."

2 Report Documentation Page Form Approved OMB No Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE SEP TITLE AND SUBTITLE Magnesium-Rich Coatings 2. REPORT TYPE 3. DATES COVERED to a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Air Warfare Center,Materials Engineering Division,22347 Cedar Point Road,Patuxent River,MD, PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR S ACRONYM(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution unlimited 11. SPONSOR/MONITOR S REPORT NUMBER(S) 13. SUPPLEMENTARY NOTES ASETSDefense 2009: Sustainable Surface Engineering for Aerospace and Defense Workshop, August 31 - September 3, 2009, Westminster, CO. Sponsored by SERDP/ESTCP. 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE unclassified Same as Report (SAR) 18. NUMBER OF PAGES 30 19a. NAME OF RESPONSIBLE PERSON Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18

3 Introduction Hexavalent chromium compounds (chromates) Gold standard in corrosion prevention Regulatory, environmental and health issues Hexavalent chromium elimination efforts Can simplify paint/depaint, decrease the cost Have led to increased corrosion failures Much work has been done on chromate-free protection systems No non-chromated primer equivalent performance

4 Introduction Topcoat Layer Aluminum Substrate Magnesium Zinc Magnesium Particles Mg-Rich Primer Layer Conversion Coating Layer Steel Cast Irons Cadmium Aluminum Alloys Silver Lead Titanium Graphite Platinum, Gold 300 Stainless Steel 400 Stainless Steel Manganese Bronze Admiralty Brass Lead-Tin Solder Copper Brass Aluminum Bronze

5 Test Plan Substrates AA2024-T3 AA7075-T6 AA2219-T87 AA2024 Al clad Primers Mg-Rich (Multiple Formulations) MIL-PRF Class C2 MIL-PRF Class N MIL-PRF Class N Conversion Coatings MIL-DTL Type I MIL-DTL Type II None (Scotchbrite TM abraded) Tests Beach-Front Exposure Salt Fog Exposure Filiform Corrosion

6 Kennedy Space Center Beach Corrosion Test Site 100 feet from mean high-tide Panels racked 30º from horizontal Beach-Front Testing

7 ASTM Standard Test Methods B 117: Neutral Salt Fog G 85, Annex 4: SO 2 Salt Fog Accelerated Testing

8 Accelerated Testing

9 First Generation Test Results AA2024-T3 (4000 hours B117) MgRich Primer-only MIL-DTL Type I Alodine 1200S No Chemical Pretreatment Scotchbrite Abrade MIL-DTL Type II Alodine T5900

10 First Generation Test Results AA2219-T87 (4000 hours B117) MgRich Primer-only MIL-DTL Type I Alodine 1200S No Chemical Pretreatment Scotchbrite Abrade MIL-DTL Type II Alodine T5900

11 First Generation Test Results AA2024-T3 (1200 hours G85 A4) MgRich Primer-only MIL-DTL Type I Alodine 1200S No Chemical Pretreatment Scotchbrite Abrade MIL-DTL Type II Alodine T5900

12 Second Generation Test Results AA2024-T3 (1200 hours G85 A4) MgRich Primer-only Gen 1 Gen 2 MIL-DTL Type I Alodine 1200S MIL-DTL Type I Alodine 1200S

13 Second Generation Test Results Primer-only panels (5000 hours B117) AA2024-T3 Mg-Rich Primer AA7075-T6 AA2024-T3 MIL-PRF-23377, Class C2 AA7075-T6

14 Second Generation Test Results MIL-PRF topcoated Mg-Rich panels (ASTM B117) AA2024-T3 AA7075-T6 1 Week (170 hours)

15 Second Generation Test Results MIL-PRF topcoated Mg-Rich panels (ASTM B117) AA2024-T3 AA7075-T6 12 Weeks (2000 hours)

16 Second Generation Test Results MIL-PRF topcoated Mg-Rich panels (ASTM B117) AA2024-T3 AA7075-T6 30 Weeks (5000 hours)

17 Second Generation Test Results MIL-PRF topcoated Mg-Rich panels (ASTM B117) AA2024-T3 AA7075-T6

18 Second Generation Test Results AA7075-T6 (336 hours G85 A4) MgRich Primer-only MIL-DTL Type II Mg-Rich Primer MIL-PRF Class N MIL-PRF Class N MIL-PRF Class C2

19 Second Generation Test Results AA7075-T6 (1500 hours G85 A4) MgRich Primer-only MIL-DTL Type II Mg-Rich Primer MIL-PRF Class N MIL-PRF Class N MIL-PRF Class C2

20 Second Generation Test Results Mg-Rich Primer MIL-PRF Class N Non-Chromium Primer (Deft 084) MIL-PRF Class N Non-Chromium Primer MIL-PRF Class C2 Hexavalent Chromium Primer

21 Second Generation Test Results MIL-PRF-85285, (1500 hours G85 A4) MIL-DTL Type II Mg-Rich Primer MIL-PRF Class N MIL-PRF Class N MIL-PRF Class C2

22 Second Generation Test Results AA2024-T3 Galvanic panels Primer-only 4 month KSC Beach Aluminum test panels with titanium, stainless steel and aluminum bolts. Mg-Rich Primer Class N Control

23 Second Generation Test Results Filiform corrosion test (1000 hours) MIL-DTL Type II MIL-PRF Topcoat Mg-Rich Primer MIL-DTL Topcoat MIL-PRF Class C2 MIL-PRF Topcoat MIL-DTL Topcoat

24 Third Generation Test Results AA2024-T3 (2000 hours B117) MgRich Primer-only

25 Third Generation Test Results AA2024-T3 (2000 hours B117) MgRich/MIL-PRF-85285

26 Modifications to Second Generation Mg-Rich AA7075-T6 (1000 hours G85 A4) MgRich Primer-only NAVAIR Non-chromium pretreatment Second Generation Mg-Rich Modification 1 Modification 3

27 Modifications to Third Generation AA7075-T6 (1000 hours G85 A4) MgRich Primer-only Third Generation Mg-Rich MIL-DTL Type II Modification 1 Modification 2 MIL-PRF Class N

28 Summary & Conclusions No single, universal test for corrosion prevention Multiple alloys, test methods and configurations Promising performance MgRich does well Primer only in neutral salt fog (5000 hours) Topcoated in SO 2 salt fog (1500 hours) Filiform corrosion tests (1000 hours) Challenges MgRich issues not seen with Class N controls Topcoated in neutral salt fog Primer only in SO 2 salt fog Downglossing of High-gloss topcoats Performance degradation on non-2000 series alloys Poor corrosion performance on steel Validation over anodize, Cd, ZnNi, IVD-Al, phosphate, etc.

29 Summary & Conclusions Under certain conditions Mg-Rich primer performs comparably to chromate primers Overall it is not equivalent to chromated OR nonchromated control primers Modifications have increased performance over various substrates Fewer ruptures through the coating and blisters Compared to the baseline early generation MgRich primers Fewer blisters and corrosion products in the scribe

30 Path Forward Testing the fourth generation is underway Commercial MgRich product NAVAIR modified MgRich Test Plan Variety of substrates Variety of exposure conditions Beach, ASTM B117, ASTM G85 Annex 4, filliform, galvanic test panels) Go/No-Go Criteria Must be better than the best non-chromate coating system Currently available and transitioned Before implementation will be authorized for Navy and Marine Corps assets

31 Acknowledgements Co-Authors: Craig Matzdorf Bill Nickerson Ed Lipnickas Panel Prep: Randy Miller Andy Schwartz Rachel Naumann Alex Everett Mg-Rich: AkzoNobel Aerospace Coatings Funding: Environmental Security Technology Certification Program